Menu Dropdowns on main menu only work for leftmost and active parent pages

After upgrading from 6.x to 7.x, I notice that I can only get drop-down menu links for the left-most menu link and active parent page menu.

When I first go to the home page, I see only drop-downs on Home:

HOME>> ABOUT-US CONTACT-US

If I click on ABOUT-US, I'll get

HOME>> ABOUT-US >> CONTACT-US

This would persist for any page that is a subitem of About-us. But once I click on the CONTACT-US, I'll get:

HOME>> ABOUT-US CONTACT-US>>

The double arrows and drop-downs disappear from the second item.

Any ideas?

Bram